COASTAL ALGORITHMS AND ON-DEMAND PROCESSING - THE LESSONS LEARNT FROM COASTCOLOUR FOR SENTINEL 3

摘要

The ESA DUE CoastColour Project has been initiated to provide water quality products for important costal zones globally. A new 5 component bio-optical model was developed and used in a 3-step approach for regional processing of ocean colour data. The L1P step consists of radiometric and geometric system corrections, and top-of-atmosphere pixel classification including cloud screening, sun glint risk masking or detection of floating vegetation. The second step includes the atmospheric correction and is providing the L2R product, which comprises marine reflectances with error characterisation and normalisation. The third step is the in-water processing which produces IOPs, attenuation coefficient and water constituent concentrations. Each of these steps will benefit from the additional bands on OLCI. The 5 component bio-optical model will already be used in the standard ESA processing of OLCI, and also part of the pixel classification methods will be part of the standard products. Other algorithm adaptation are in preparation. Another important advantage of the CoastColour approach is the highly configurable processing chain which allows adaptation to the individual characteristics of the area of interest, temporal window, algorithm parametrisation and processing chain configuration. This flexibility is made available to data users through the CoastColour on-demand processing service. The complete global MERIS Full and Reduced Resolution data archive is accessible, covering the time range from 17. May 2002 until 08. April 2012, which is almost 200TB of in-put data available online. The CoastColour on-demand processing service can serve as a model for hosted processing, where the software is moved to the data instead of moving the data to the users, which will be a challenge with the large amount of data coming from Sentinel 3.